Herbert Leopold GABRYŚ
Power industry in Poland in 2014. From the results of the year 2013 and not only – strongly authorial judgments
Presented is a statement of figures characterizing disadvantageous changes in macroeconomic situation of energy sectors that occured in the year 2013. Attention is called to the fact that the first months of this year do not send signals of a possible dramatic change of these unfavourable tendencies for they do not result either from much smaller than desirable rise in wholesale marketing electric energy prices or from production and sales volume, as it does not grow up, and certainly not from the still unreadable legislative signals. The deepening loss of credibility of the latter becomes today the most important barrier for strategic investment decisions.
Keywords: Polish power industry, the 2013 economic results, characteristics of costs
Marek AUGUSTYNIAK, Zbigniew USAREK, Bolesław AUGUSTYNIAK
Hierarchy of influence factors in diagnostics of steel components using static stray field
Electromagnetic methods have a special place among NDT techniques of steel components, for their cost-efficiency, cleanness, rapidity and adaptability. However, they exhibit significant limitations, which tend to be underscored by promoters of the so-called metal magnetic memory (MMM) where their major proposal involves possibility of quantitative correlation of stray fields characteristics with the local stress state. The presented work contains a critical assessment and fundamental reinterpretation of the already published results [3]. The authors’ own measurements and magnetic simulation using Finite Element Method allow concluding that a certain local magnetic field gradient depends on a combination of four factors: microstructure, residual magnetisation, object’s geometry and finally the stress state. In the analysed realistic case the last factor, though the most important from the engineering point of view, has relatively least influence on the stray field characteristics. Consequently, it is impossible to define a reverse function allowing explicit determination of local stresses with the use of MMM methodology.
Keywords: Metal Magnetic Memory, magnetic stray field, magnetic NDT, Finite Element Method
Jacek MALKO
The Decalogue of the USA power industry development trends
Discussed are here the current development trends in the American power industry in disaggregation for several fields regarded as the key ones. Determined is, on a basis of literature sources, their potential influence on the energy sector future. Ascertained is also that new technical conditions, changes in the market behaviour, more frequent climatic anomalies and new regulations and policies are the factors shaping today the future of energy systems. Attention is called to the fact that this dependency can be observed on a global scale, both in developed and emerging countries. The author confirms the opinion that many elements of policy, regulations and energy markets as well as the costs and achievements of the existing and new technologies make it difficult to consider processes occurring in energy systems and the electric energy itself as a commodity. He also regards as indispensable the need to identify the main causative factors even when you are aware of imperfection of the performed analyses and estimations.
Keywords: USA power industry, development trends, present-day development priorities
Robert CHOLEWA
Power unit work with slip parameters – a report on measurement and analytic experience
Presented is a review of measurement and analytic experience in operation of a power unit working with slip steam parameters. It is proved that the work of a unit with all valves opened – with a full slip – is cost-effective for units working previously with quantity (throttle) control. In the analysed case the decrease of a net specific fuel chemical energy consumption for a unit working with slip parameters equalled about 1% with a load on a level of 60% of a nominal load. With quantity and quality control the conversion to work with a slip steam pressure before the turbine was not profitable in any of the three analysed cases. Net index increase amounted from 0,2 to 1,2% for a load on a level of 60% of the nominal load. The deterioration of a power unit work with all valves opened before the high-pressure section results mainly from the decrease of isentropic enthalpy drop in the turbine flow system. With the quantity and quality control we can obtain a change in a power unit output partially by reduction of the control stage arc admission and steam throttling does not cause so many losses as the quality control. Nonetheless, even with quantity and quality control we can select the modified steam pressure before the turbine as well as the mode of opening of each individual control valve so as to obtain better net power unit operation indices than the ones concerning rated steam parameters before the turbine. We can estimate obtaining the reduction of the net specific fuel chemical energy consumption on the level of up to 0,5% with about 55% load.
Keywords: power unit, slip parameters, measurement and analytic experience
Łukasz TOMCZAK
Subcooling of boiler flue gases – practical aspects
The level of an outlet loss has a vital influence on a boiler efficiency as this loss accounts for about 80% of all boiler heat losses. Decrease of the outlet loss consists first of all in operation with reduced combustion air volume and reduction of flue gas temperature behind the boiler. During the last several years a technology of flue gas heat recovery has been developed – additional heat exchangers are mounted in a flue gas duct behind the boiler. The installations used nowadays allow taking better advantage of a fuel combustion energy e.g. for the combustion air needs or in some other technological processes. Enhancement of a boiler efficiency enables reduction of fuel consumption but lowering of the flue gas temperature carries the risk of acid forming and sediment agglomeration so it is necessary to apply polymers and the heat exchange surface must be regularly washed.
Keywords: boiler efficiency, outlet loss level, flue gas subcooling
Jacek LEPICH
Influence of DeNOx installation on the change of flue gas fans working parameters – measurement experience in the aspect of fans modernization
Discussed are implementation effects of nitrogen oxides reduction (with the use of SCR method) installation on the change of flue gas fans working parameters. Described is briefly a principle of SCR method operation and types of catalysts. Presented are methods of taking measurements with the aim to check fan reserves for the possibility to mount the SCR installation. Quoted are measurement examples of the specified flue gas flow resistances on SCR catalysts. Shown are effects of fans modernization carried out with regard to future installation of SCR system. Presented is the characteristics of flue gas fan operating points (network resistance) before and after installing the catalyst as well as the characteristics of active power consumption as a function of fan efficiency, depicting economic effects of replacing the efficiency control method with a more energy-saving one.
Keywords: NOx reduction installation, influence on fan operation, measurement experience
Sławomir RAJCA, Sylwia DANISZ-KUCHTA
Problems concerning steam turbine blade systems connected with standstill corrosion and sediment accumulation
Proved is that blade system damages in the form of sediments accumulated on blades and material losses caused by standstill corrosion can lead to, among the others, a TG unit power output and efficiency reduction. For many reasons, including technical and economic ones, such occurences should be prevented. The Pro Novum Department for Power Chemistry has enough knowledge, experience and potential to effectively diagnoze a source of sediment emission as well as standstill corrosion causes and can successfully remove or at least considerably reduce the influence of the discussed negative effects on efficiency of a blade system.
Keywords: steam turbines, blade systems, standstill corrosion, sediment accumulation, Pro Novum
Paweł GAWRON, Przemysław JURASZ
Changes in guidelines concerning the quality of a circulating agent in water/steam systems of power units
The current operation of electrical power equipment and the hitherto gained knowledge have allowed elaboration of precise guidelines concerning circular agents quality regimes. The actual recommendations enable not only taking into account the working parameters, construction and individual conditionings of a given object but also apply them for various operating conditions of the device. It allows then the safe, failure-free operation that does not generate additional costs connected with damages, forced standstills and unexpected situations.
Keywords: water/steam systems of power units, circulating agent quality guidelines
Paweł GAWRON, Sylwia DANISZ-KUCHTA
From diagnostic examinations and analysis of the equipment service conditions to the system monitoring of their lifetime – experiences connected with LM System PRO+® using
The proper assessment is possible due to the knowledge about working parameters of power equipment – including the integration of data about the physical and chemical control and the data characterising the present stage of operation of the equipment, as well as the knowledge resulting from the overhaul diagnostics. Diagnostics is an important element of technical maintenance of power equipment, properly performed it provides the knowledge necessary to plan the dates and scopes of overhauls, to forecast the lifetime and to introduce the effective prevention. To be able to do so the diagnostics shall present a professional level.
Keywords: diagnostics thermo-mechanical power equipment, IT Platform LM System PRO+